Ventilating-fan structure



PATBNTBD PBB.,2Ja,-19lo4. w. CLIFFORD. VBNTILATING FAN STRUCTURE.

APPLICATION PILEDJUNE 8, 1903.

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|uvENTon UNITED STATES Patented February 23, 1904.

YPATENT OFFICE.

IVILLIAM CLIFFORD, OF JEANNTTE, PENNSYLVANIA,

YVENTlLATING-FAN STRUCTURE.

SPECIFICATION forming part of Letters Patent No. 752,956, dated February 23, 1904. Application led June `8, 1903. Serial No. 160,599( (No model.)

To a/ZZ whom, t may concern; K

Be it known that I, WILLIAM GLmEoRD, a citizen of the United States, residing at Jeannette, in the county of Westmoreland and State of Pennsylvania, have invented or discovered certain new and useful Improvements in Ventilating-Fan Structures, of which, improvements 'the following is a specification.

My improvements concern the construction of centrifugal-fan apparatus.

rIhe object of my invention is a construction of the discharge-passages from such a fan-a construction such as to increase the efficiency of the fan.

The fan to which my invention appertains is one of a class which are primarilyv used for Ventilating purposes-to impel a current of air to and from a mine, a building, or other place requiring ventilation. A centrifugal fan is a fan of rotary type. It takes its supply of air through an axially-arranged opening or openings and discharges the current of air which it generates from its periphery. The delivery-chamber of such a fan is commonly of spiral form, and from the delivery-chamber the current of air is led off. It is common in the installation of these fans to provide two passages leading from the delivery-chamber, the one leading to the place to be ventilated, the other opening to the atmosphere, and to provide a valve capable of moving to close one or the other of these two passages and at the same time to leave the other passage open. It is to the construction of these passages and this valve that my invention is directed. This alternative discharge-passage finds its most important use when cooperating with a plurality of passages leading to the fan on its supply side. These fans are commonly constructed so that they may take air either directly from the atmosphere or through a passage from the place to be ventilated. W'hen taking air directly from the atmosphere, a proper location of the valve on the discharge side of the fan will cause the current to iiow to the place to be ventilated, and when the fan is taking air from the place to be ventilated a proper shifting of the valve will cause the current to be discharged directly to the atmosphere. In the former case the fan acts as a blowing-fan. In the latter it acts as an exhaust-fan.

In the accompanying drawings, which form part of this specification, Figure l is a view in of the fan serves to supply air. It will be un-y derstood that the supply of air may be taken either from the .atmosphere or from a place to be ventilated. Particular means of effecting this alternative supply are Well known in the art and are not detailed here. The delivery-chamber 4 opens through a throat 4l into a chimney-passage 42. From throat 4l a conduit 43 also leads. This conduit conveys the air-current to the place to be ventilated when the fan is blowing, and I shall refer to it hereinafter as the blowing-passage. l In throat 4l a valve or door 5 is placed, and this 4valve or door is so arranged that within its range of movement it obstructs alternately the passage to chimney 42 and the passage to conduit 43, leaving the other passageopen to the :How of the current.

It has been found that to obtain the best results the chimney-passage should in shape approximate a spiral continuous with the delivery-chamber and that the blowingpassagev should be choked or constricted. The contour of the spiral, the degree of its flare, is a matter dependent on the temperament of the particular mine. (Temperament is a term which indicates the resistance which a mine offers to the Ventilating-current.) It has heretofore beena problem in constructing these fans to maintain the contours of the chimney-passage and the blowing-passage in their most effective proportions. 'The door should be so constructed that when closing the blowing-passage and leaving the chimney-passage open it will conform to the spiral wall of the passage; but when so constructed its length hasbeenasource of diiiiculty,for in its alternate position it must span the chimney-passage, and the length of that span is commonly less than the span of the blowing-passage upon the line of the spiral wall of the chimney-passage..

In order to meet this difficulty, a departure from the preferred .passage contours has been resorted to, and the construction of the door itself has been modied; but the diiiculty has not been overcome heretofore with entire satisfaction.

In my improved construction the door 5 has a general curved contour, such that when lowered to close the blowing-passage and leave the chimney-passage open it substantially conforms to the wall of the spiral passage. Door 5 rests upon a support 51, (which may be and preferably is a roller suitably disposed at or near the upper end of the door,) and the lower end of the door is supported when in its two operative positions in any desired manner, as by the mechanism presently to be described. The position of support 51 relative t0 the wall of chimney-passage 42 is such that as door 5 is raised from the position shown in full lines in Fig. 1 and in dotted lines in Fig. 2 to the position shown in full lines in Fig. 2 and in dotted lines in Fig. 1 the door swings and slides upon the support and a portion of it retires over the support and extends outside of the throat, as the drawings indicate. In consequence of this construction I am able to employ the preferred contours of the several passages unmodied and am able to employ a door which conforms to the spiral passage wall when the chimney is open. My improved door possesses the further advantage that when it is raised and blowing-passage 43 is 'open the convex side of the curved door is outward, and this curvature may be advantageously employed as a constriction of the opening to the conduit.

In order to avoid the formation of an eddy in the gullet at support 51 when blowing-passage 43 is open, I form upon the under side of door 5 a shield 52, adapted to be adjacent to support 51 when the door is raised and to deflect the stream as it passes support 51.

My preferred means of operating the door are indicated in the drawings. provided to control the movement of the door. These guides are preferably constructed as shown. Arms 53 project from the edges of door 5 upon either side and intov channels 54,

Guides are formed in the passage-wall and arranged so as to bring door 5 to its two operative positions as it is raised and lowered. Ropes and Winches (indicated at 55 and 56) may be employed to raise and lower the door and hold it supported in its operative position.

I claim herein as my invention- 1. In a centrifugal-fan construction, a delivery-chamber, a chimney-passage, and a blowing-passage, in combination with a door adapted to control said passages, and a support for said door, the said door being movable laterally and longitudinally on its support, substantially as described.

2. In a centrifugal-fan construction, a delivery-chamber, a chimney-passage, and a blowing-passage, in combination with a swinging and sliding door having a curvature whereby when in position across the blowing-passage it forms a continuation of the spiral wall of the chimney-passage and when in position across the chimney-passage it forms part of the constricted gullet in the blowing-passage, substantially as described.

3. In a centrifugal-fan construction having a delivery-chamber, a chimney-passage, and a blowing-passage, the combination of a door adapted to control said passages, a support for said door, and a shield formed upon said door adapted when the door is in position to close the chimney-passage to stand inoperative relation to the support, substantially as described.

4. In a centrifugal-fan construction having a delivery-chamber, a chimney-passage, and a blowing-passage, the combination of aswinging and sliding door adapted to control said passages, a support for said door upon which said door is adapted to swing and slide, and means for swinging and sliding said door to its several operative positions, substantially as described.

5. In a centrifugal-fan construction having a delivery-chamber, a chimney-passage, and a blowing-passage, the combination of a swinging and sliding door adapted to control said passages, a support for said door upon which the said door is adapted to swing and slide, and guides adapted to control the movement of the door, substantially as described.

In testimony whereof I have hereunto set my hand.

WILLIAM CLIFFORD. Witnesses F. E. GAITHER, BAYARD H. CHRISTY.

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